Composite panels with adhesive and separate fragment layers

ABSTRACT

A panel and a method for manufacturing thereof where the panel includes a first layer comprising a first blend of paper fragments and plastic fragments; a second layer comprising a second blend of paper fragments and plastic fragments, wherein the paper fragments and plastic fragments of the second blend are coated with an adhesive; and a third layer comprising the first blend of paper fragments and plastic fragments, wherein the second layer is disposed between the first layer and the third layer, and wherein the first layer, the second layer, and the third layer are combined to form the panel using heat and pressure. In another embodiment, the paper fragments and plastic fragments of the first blend, not the second blend, are coated with an adhesive.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

None.

BACKGROUND

Low slope commercial roofs are typically comprised of four essentiallayers. The base of the assembly is typically a fluted steel deck. Lessfrequently, oriented strand board (OSB), plywood, or concrete are usedas decking. A rigid insulating foam board, such as polyisocyanurate foamboard or expanded polystyrene, is installed directly over the deck. Aprotective cover board is positioned directly over the insulating foamand is typically secured with screws that extend through the insulatingfoam and into the deck. A water-resistant membrane is then installedover the protective cover board and is attached to the cover board witheither adhesives or induction welding. Cover boards, and other buildingmaterials, can be manufactured from a variety of waste productsincluding municipal solid waste (MSW), residuals from recycling centers,industrial waste, and other waste sources.

SUMMARY

Aspects of one embodiment of the present disclosure relate to a panel.The panel may include a first layer containing a first blend of paperfragments and plastic fragments; a second layer containing a secondblend of paper fragments and plastic fragments, wherein the paperfragments and plastic fragments of the second blend are coated with anadhesive; and a third layer containing the first blend of paperfragments and plastic fragments, wherein the second layer is disposedbetween the first layer and the third layer, and wherein the firstlayer, the second layer, and the third layer are combined to form thepanel using heat and pressure. In another embodiment, paper fragmentsand plastic fragments in the first and third layers are coated with anadhesive, while the fragments in the second layer are not.

Aspects of another embodiment of the present disclosure relate to amethod for manufacturing a panel. The method may include obtaining paperfragments and plastic fragments; mixing the paper fragments and theplastic fragments into a first blend of paper and plastic fragments;mixing the paper fragments and the plastic fragments into a second blendof paper and plastic fragments; coating the paper fragments and theplastic fragments of the second blend with an adhesive; forming a matcomprising separate layers of the first blend and the second blend; andconsolidating the mat using heat and pressure to form a panel. In oneembodiment, a first layer comprises the first blend; a second layercomprises the second blend, and a third layer comprising the firstblend. In an alternative embodiment, a first layer comprises the secondblend; a second layer comprises the first blend, and a third layercomprising the second blend.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 is a side cutout view of an example panel according to anembodiment.

FIG. 2 is a side cutout view of another example panel according toanother embodiment.

FIG. 3 is a flow diagram depicting operations in a panel manufacturingprocess, in accordance with an example embodiment.

FIG. 4 is a flow diagram depicting operations in a panel manufacturingprocess, in accordance with another example embodiment.

FIG. 5 is a table comparing various example panels, in accordance withvarious embodiments.

DETAILED DESCRIPTION

The cover board and method of manufacturing thereof discussed hereinhave many advantages over conventional products and methods. The coverboard may be manufactured from small, shredded pieces of recycledmaterial, allowing for use of a greater variety of materials thanconventional methods of manufacture that rely upon large, cohesivematerials. This also allows for the physical characteristics of thecover board to be modified based on an intended application much moreeasily than conventional methods of manufacture. The cover board mayinclude different layers of paper and plastic fragments resulting ingreater strength and/or stiffness than conventional cover boards withoutlayers of paper and plastic fragments. The cover board may also bemanufactured using a hot-press process which is a simpler manufacturingprocess than conventional thermoplastic conversion processes thatutilize injection molding, extrusion, thermoforming, or film-blowing.This process may also allow for the production of cover boards at afaster production rate and a lower overall manufacturing cost ascompared to conventional production methods, especially when adhesivesare used in the second fragment layer of the panel. This process mayalso allow for the production of cover boards at a much lower processingtemperature than that associated with conventional methods. Use of anadhesive can also yield cover boards with higher strength, greaterstiffness, and a lower coefficient of thermal expansion thanconventional cover boards that are made without an adhesive in thesecond fragment layer of the panel.

FIG. 1 is a side cutout view of an example panel 100. The panel 100 mayinclude a first layer 110, a second layer 120, and a third layer 130. Insome embodiments, the first layer 110 may be omitted. In otherembodiments, the third layer 130 may be omitted. In yet otherembodiments, the first layer 110 and third layer 130 may be omitted. Thefirst layer 110 may include a first blend of paper and plasticfragments. The first blend may be a uniform mixing of paper and plasticfragments, a non-uniform mixing of paper and plastic fragments, or aspecific arrangement of paper and plastic fragments. The second layer120 may include a second blend of paper and plastic fragments coatedwith an adhesive. Similar to the first blend, the second blend may be auniform mixing of paper and plastic fragments, a non-uniform mixing ofpaper and plastic fragments, or a specific arrangement of paper andplastic fragments. The third layer 130 may include a third blend ofpaper and plastic fragments. The third blend may be a uniform mixing ofpaper and plastic fragments, a non-uniform mixing of paper and plasticfragments, or a specific arrangement of paper and plastic fragments. Thethird blend may be the same as the first blend. In another embodiment,the first layer 110 and/or third layer 130 may include a second blend ofpaper and plastic fragments coated with an adhesive, while the secondlayer 120 is not coated with adhesive. The second layer 120 is disposedbetween first layer 110 and the third layer 130. The first layer 110 andthird layer 130 may have the same thickness. The second layer 120 mayhave a thickness greater than that of the first layer 110 and/or thethird layer 130. In other embodiments, the second layer 120 may have athickness less than that of the first layer 110 and/or the third layer130. In some embodiments the panel may have a length of about 8 feet, awidth of about 4 feet, and a thickness of about 0.125-1.5 inches. Inother embodiments, the composite might be cut into the shape of boards,such as boards having a dimension of 16 feet long, a width of 8 inches,and a thickness of about 0.5 inches.

Paper fragments of the first layer 110, second layer 120, or third layer130 may include recycled materials. The paper may be recycled or sourcedfrom waste streams. Use of recycled materials has the advantage of beinglow-cost. Also, diversion of the paper from landfills prevents the paperfrom being slowly decomposed and converted to greenhouse gases. Paperfragments may include newspaper, advertising, office paper, packaging,or other paper products. The paper fragments may be shredded fragmentsof larger recycled objects or materials. In some embodiments the paperfragments may have a thickness of less than about 0.01 inches. In otherembodiments the paper fragments may have a thickness of less than about0.002 inches.

Plastic fragments of the first layer 110, second layer 120, or thirdlayer 130 may include recycled materials. The plastic fragments mayinclude polypropylene, polystyrene, polyester, nylon, rubber (naturaland synthetic), polyvinyl chloride (including flexible and ridged),polyethylene (including LLDPE, LDPE, MDPE, HDPE), copolymers of ethyleneand propylene, and other commercial plastics. The plastic fragments maybe a mixture of different types of polymers. The plastic fragments mayinclude plasticizers, such as dioctyl phthalate or benzyl butylphthalate, colorants, stabilizers, preservatives, and other functionaladditives. The plastic may be recycled or sourced from industrial wastestreams which has the advantage of being low-cost. Also, diversion ofthe plastic from landfills prevents the paper from being slowlydecomposed and converted to greenhouse gases. The plastic may be sourcedfrom plastic films, packaging, or other recyclable plastics. The plasticfragments may be shredded fragments of larger recycled objects ormaterials. In some embodiments the plastic fragments may have athickness of less than about 0.01 inches. In other embodiments, theplastic fragments may have a thickness of less than about 0.002 inches.

In some embodiments individual fragments of the first layer 110, secondlayer 120, and third layer 130 may include paper and plastic. In yetother embodiments, the individual fragments may include metal. Forexample, fragments may be sourced from packaging including many layersof paper and plastic. Shredding this packaging results in fragmentscontaining both paper and plastic. Some packaging also includes a layerof aluminum foil or a film that has been metallized on one surface.Shredding this packaging results in discrete fragments that each containpaper layers, plastic layers, and one or more metal layers.

The first blend may represent a first paper/plastic ratio. In someembodiments the paper fragments of the first blend may be 20-90% of thefirst blend by weight and the plastic fragments of the first blend maybe 10-80% of the first blend by weight. In other embodiments the paperfragments of the first blend may be 45-65% of the first blend by weightand the plastic fragments of the first blend may be 35-55% of the firstblend by weight. In yet other embodiments, the paper fragments of thefirst blend may be 75-80% of the first blend by weight and the plasticfragments of the first blend may be 20-25% of the first blend by weight.The first blend may be a homogenous mixture of paper and plasticfragments. In some embodiments the first blend may include fragmentsthat comprise alternating paper layers, plastic layers, and optionallymetal layers.

The second blend may represent a second paper/plastic ratio. The secondpaper/plastic ratio may be the same as the first paper/plastic ratio orit may be different. In some embodiments the paper fragments of thesecond blend may be 30-90% of the second blend by weight and the plasticfragments of the second blend may be 10-70% of the second blend byweight. In other embodiments the paper fragments of the second blend maybe 50-75% of the second blend by weight and the plastic fragments of thesecond blend may be 30-55% of the second blend by weight. In yet otherembodiments, the paper fragments of the second blend may be 75-80% ofthe second blend by weight and the plastic fragments of the second blendmay be 20-25% of the second blend by weight. The second blend may be ahomogenous mixture of paper and plastic fragments. In some embodimentsthe second blend may include fragments that comprise alternating paperlayers, plastic layers, and optionally metal layers.

In some embodiments the paper and plastic fragments of the second layer120 or of the second blend may be coated with an adhesive. The adhesivemay be about 1-20% of the second layer 120 by weight. In someembodiments the adhesive may be about 2-8% of the second layer 120 byweight. The adhesive may be a thermoplastic adhesive or a thermosettingadhesive. Thermosetting adhesives include isocyanates, polyurethanes,polyurea resins, phenolic resins, amino resins (includingurea-formaldehyde resins, melamine-formaldehyde resins, ormelamine-urea-formaldehyde resins), epoxy resins (including two-partliquid epoxy resins or one-part powdered epoxy resins), crosslinkedpolysaccharides, and resins based on soy and poly(amide epichlorohydrin)(PAE). Thermoplastic adhesives include latex emulsions, powderedpolyethylene, powdered polypropylene, powdered copolymers of ethyleneand propylene, powdered polystyrene, and other polymeric powders with amelt-point that is less than about 350° F. The adhesive used for coatingthe paper and plastic fragments of the second layer 120 may be selectedbased on an intended application of the panel or required physicalattributes of the panel. For example, for a panel application requiringa stiff panel, a thermosetting adhesive with a high level ofcrosslinking will be useful to maximize the modulus of elasticity of thecomposite. In another example, a panel application requiring a highimpact resistance, a thermosetting adhesive with a low level ofcrosslinking will be useful to improve the toughness of the panel andits ability to absorb and dissipate kinetic energy from an impact.

In some embodiments the paper and plastic fragments of the first layer110 and/or the third layer 130 of the first blend may be coated with anadhesive. The adhesive may be about 1-20% of the first layer 110 orthird layer 130 by weight. In some embodiments the adhesive may be about2-8% of the first layer 110 or third layer 130 by weight. The adhesivemay be a thermoplastic adhesive or a thermosetting adhesive.Thermosetting adhesives include isocyanates, polyurethanes, polyurearesins, phenolic resins, amino resins (including urea-formaldehyderesins, melamine-formaldehyde resins, or melamine-urea-formaldehyderesins), epoxy resins (including two-part liquid epoxy resins orone-part powdered epoxy resins), crosslinked polysaccharides, or resinsbased on soy and poly(amide epichlorohydrin) (PAE). Thermoplasticadhesives include latex emulsions, powdered polyethylene, powderedpolypropylene, powdered copolymers of ethylene and propylene, powderedpolystyrene, and other polymeric powders with a melt-point that is lessthan about 350° F. The adhesive used for coating the paper and plasticfragments of the first layer 110 or the third layer 130 may be selectedbased on an intended application of the panel or required physicalattributes of the panel. For example, for a panel application requiringa stiff panel, a thermosetting adhesive with a high level ofcrosslinking will be useful to maximize the modulus of elasticity of thecomposite. In another example, a panel application requiring a highimpact resistance, a thermosetting adhesive with a low level ofcrosslinking will be useful to improve the toughness of the panel andits ability to absorb and dissipate kinetic energy from an impact.

In some embodiments the paper and plastic fragments of the second layer120 or of the second blend may be coated with an adhesive while thepaper and plastic fragments of the first layer 110 and the third layer130 or of the second blend are not coated with an adhesive. In otherembodiments, the paper and plastic fragments of the first layer 110 andthe third layer 130 or of the second blend may be coated with anadhesive while the paper and plastic fragments of the second layer 120or of the second blend are not coated with an adhesive. In yet otherembodiments the paper and plastic fragments of the second layer 120 orof the second blend as well as the paper and plastic fragments of thefirst layer 110 and the third layer 130 or of the second blend may becoated with an adhesive.

The first layer 110, second layer 120, and third layer 130 may includeadditional materials. The layers may include preservatives, colorants,water repellents, fire retardants, odor blockers, adhesion promoters,fibers, and other functional additives. In some embodiments additives ina layer will be less than about 5% of the layer by weight. The secondlayer 120 may include filler material. The filler material may be almostany material coated with the adhesive. For example, the second materialmay include gravel coated with the adhesive.

In some embodiments, it will be advantageous to treat the fragments inthe first layer 110, second layer 120, and third layer 130 with atackifying resin. In other embodiments, a tackifying resin can beapplied to only the first layer 110 and the third layer 130. Optionally,the tackifying resin can be applied to only one fragment layer or anycombination of fragment layers. Tackifying resins can include aminoresins, certain epoxy resins, certain polyurethane resins, certainresins based on terpenes, or other substances that impart a level ofstickiness to the fragments.

FIG. 2 is a side cutout view of another example panel 200. The panel 200may include a first layer 210, a second layer 220, a third layer 230, afirst exterior layer 240 and a second exterior layer 250. The firstlayer 210, the second layer 220, and the third layer 230 may be the sameas or similar to the first layer 110, the second layer 120, and thethird layer 130, respectively, of FIG. 1 . For example, the first layer210 and the third layer 230 may include paper and plastic fragments ofthe first blend while the second layer 220 may include paper and plasticfragments of the second blend. Additionally, in some embodiments thepaper and plastic fragments of the second layer 220 or of the secondblend may be coated with an adhesive while in other embodiments, thepaper and plastic fragments of the first layer 210 and/or third layer230 or of the first blend may be coated with an adhesive. In someembodiments, the first layer 210 may be omitted. In other embodiments,the third layer 230 may be omitted. In yet other embodiments, the firstlayer 210 and third layer 230 may be omitted. In further embodiments,the first exterior layer 240 may be omitted. In other furtherembodiments, the second exterior layer 250 may be omitted. The secondlayer 220 is disposed between first layer 210 and the third layer 230.The first exterior layer 240 and the second exterior layer 250 aredisposed on opposite exterior faces of the panel 200. The first layer210 and the third layer 230 may have the same thickness. The firstexterior layer 240 and the second exterior layer 250 may have the samethickness. The first layer 210 and the third layer 230 may each have athickness greater than the thickness of the first exterior layer 240and/or the second exterior layer 250. The second layer 220 may have athickness greater than that of the first layer 210 and/or the thirdlayer 230. In some embodiments the panel may have a length of about 8feet, a width of about 4 feet, and a thickness of about 0.125-1.5inches. In other embodiments, the composite might be cut into the shapeof boards, such as boards having a dimension of 16 feet long, a width of8 inches, and a thickness of about 0.5 inches. In other embodiments, thecomposite could have a length of about 0.1-60 feet, a width of about0.1-24 feet, and a thickness of about 0.1-2.0 inches.

In some embodiments the paper and plastic fragments of the second layer220 or of the second blend may be coated with an adhesive. The adhesivemay be about 1-20% of the second layer 220 by weight. In someembodiments the adhesive may be about 2-8% of the second layer 220 byweight. The adhesive may be a thermoplastic adhesive or a thermosettingadhesive. Thermosetting adhesives include isocyanates, polyurethanes,polyurea resins, phenolic resins, amino resins (includingurea-formaldehyde resins, melamine-formaldehyde resins, ormelamine-urea-formaldehyde resins), epoxy resins (including two-partliquid epoxy resins or one-part powdered epoxy resins), crosslinkedpolysaccharides, and resins based on soy and poly(amide epichlorohydrin)(PAE). Thermoplastic adhesives include latex emulsions, powderedpolyethylene, powdered polypropylene, powdered copolymers of ethyleneand propylene, powdered polystyrene, and other polymeric powders with amelt-point that is less than about 350° F. The adhesive used for coatingthe paper and plastic fragments of the second layer 220 may be selectedbased on an intended application of the panel or required physicalattributes of the panel. For example, for a panel application requiringa stiff panel, a thermosetting adhesive with a high level ofcrosslinking will be useful to maximize the modulus of elasticity of thecomposite. In another example, a panel application requiring a highimpact resistance, a thermosetting adhesive with a low level ofcrosslinking will be useful to improve the toughness of the panel andits ability to absorb and dissipate kinetic energy from an impact.

In some embodiments the paper and plastic fragments of the first layer210 and/or the third layer 230 of the first blend may be coated with anadhesive. The adhesive may be about 1-20% of the first layer 210 orthird layer 230 by weight. In some embodiments the adhesive may be about2-8% of the first layer 210 or third layer 230 by weight. The adhesivemay be a thermoplastic adhesive or a thermosetting adhesive.Thermosetting adhesives include isocyanates, polyurethanes, polyurearesins, phenolic resins, amino resins (including urea-formaldehyderesins, melamine-formaldehyde resins, or melamine-urea-formaldehyderesins), epoxy resins (including two-part liquid epoxy resins orone-part powdered epoxy resins), crosslinked polysaccharides, or resinsbased on soy and poly(amide epichlorohydrin) (PAE). Thermoplasticadhesives include latex emulsions, powdered polyethylene, powderedpolypropylene, powdered copolymers of ethylene and propylene, powderedpolystyrene, and other polymeric powders with a melt-point that is lessthan about 350° F. The adhesive used for coating the paper and plasticfragments of the first layer 210 or the third layer 230 may be selectedbased on an intended application of the panel or required physicalattributes of the panel. For example, for a panel application requiringa stiff panel, a thermosetting adhesive with a high level ofcrosslinking will be useful to maximize the modulus of elasticity of thecomposite. In another example, a panel application requiring a highimpact resistance, a thermosetting adhesive with a low level ofcrosslinking will be useful to improve the toughness of the panel andits ability to absorb and dissipate kinetic energy from an impact.

In some embodiments the paper and plastic fragments of the second layer220 or of the second blend may be coated with an adhesive while thepaper and plastic fragments of the first layer 210 and the third layer230 or of the second blend are not coated with an adhesive. In otherembodiments, the paper and plastic fragments of the first layer 210 andthe third layer 230 or of the second blend may be coated with anadhesive while the paper and plastic fragments of the second layer 220or of the second blend are not coated with an adhesive. In yet otherembodiments the paper and plastic fragments of the second layer 220 orof the second blend as well as the paper and plastic fragments of thefirst layer 210 and the third layer 230 or of the second blend may becoated with an adhesive.

The first exterior layer 240 and the second exterior 250 may include anintractable material. An intractable material is a polymeric materialwhich is insoluble in water and which has a melting point greater thanabout 350 degrees Fahrenheit. For example, an intractable material maybe paper, woven cellulosic fabrics, hydroentangled cellulosic nonwovenfabrics, nylon film, polyester film, nylon nonwoven fabrics, polyesterglass woven roving, metallic foils, and other thin sheet or roll goodshaving a melting point above 350 degrees Fahrenheit. In some embodimentsthe first exterior layer 240 and the second exterior layer 250 includean intractable material having a melting point greater than 450 degreesFahrenheit or an intractable material having no recognized meltingpoint. Additionally, intractable materials can include multi-layeredlaminates, such as laminates comprised of a layer of nylon and a layerof polyethylene, laminates comprised of a layer of polyester and a layerof polyethylene, or laminates comprised of a layer of polyester, a layerof paper, and a layer of polyethylene. In these examples, thepolyethylene layer is not intractable, but functions as a thermoplasticbinder.

The first exterior layer 240 may be attached to the first layer 210 andthe second exterior layer 250 may be attached to the third layer 230 inorder to sandwich panel 200. The first exterior layer 240 may beattached to the first layer 210 by a thermoplastic adhesive, athermosetting adhesive, or a mechanical fastening system. In someembodiments the thermosetting adhesive used to attach the first exteriorlayer 240 to the first layer 210 may be a thermosetting adhesive used tocoat the fragments of the second layer 220.

The first exterior layer 240 and the second exterior layer may cover aportion of an area of the panel 200 or the entirety of the area of thepanel 200. The first exterior layer 240 and second exterior layer 250may cover identical or mirror areas of the panel on opposite exteriorsurfaces of the panel. The first exterior layer 240 and the secondexterior layer 250 may each have a thickness greater than about 0.00001inches and less than about 0.20 inches. The first exterior layer 240 andthe second exterior layer 250 may together be about 1-20% of the panelby weight.

FIG. 3 is a flow diagram depicting operations in a panel manufacturingprocess 300, in accordance with an example embodiment. Additional,fewer, or different operations may be performed in the method, dependingon the embodiment. Further, the operations may be performed in the ordershown, concurrently, or in a different order. At 310 paper and plasticfragments are shredded. The paper and plastic fragments may be shreddedfrom existing fragments, or by shredding larger objects or materials.The paper and plastic fragments may be shredded from new material orfrom recycled objects or material. In some embodiments the paper andplastic fragments are obtained without shredding. Paper and plasticshredding can be done by a common machine or using a different shredderfor paper than a shredder for plastic.

At 320 the paper and plastic fragments are processed through one or morescreens. Processing the fragments through screens may be done to achievea certain size of fragments or to screen out other material. Forexample, paper fragments can be obtained by milling pieces of paperuntil the fragments pass through a 1-inch mesh screen. Screens withlarger or smaller mesh sizes may be used. In another example, paperfragments are obtained by shredding recycled paper until the paperfragments pass through a 19-mm mesh screen and plastic fragments areobtained by shredding recycled plastic film until the plastic fragmentspass through a 19-mm mesh screen. If multiple screens are used, thescreens may or may not have the same size apertures in the mesh.

At 330 the paper and plastic fragments may be treated. In someembodiments the fragments may be treated using one or moremultifunctional aldehydes or a treatment composition derived from ureaand one or more multifunctional aldehydes. Treating the fragments withone or more multifunctional aldehydes or a treatment composition derivedfrom urea and one or more multifunctional aldehydes may crosslinkendotoxins of the fragments. For example, the fragments may be treatedby loading the fragments into a rotary blender and spraying thefragments with a urea-glutaraldehyde solution while rotating at 10 rpm.In some embodiments the molar ratio of urea to glutaraldehyde in thesolution may be greater than 1. In other embodiments, the fragments maybe treated using one or more antimicrobial agents.

At 340 the paper and plastic fragments are dried. The paper fragmentsand plastic fragments may be dried separately or together. The paperfragments and/or the plastic fragments may be dried in a rotary drier.For example, the fragments may be dried in a rotary drier with an inlettemperature of about 250° F. and an outlet temperature of about 180 Ffor a period of about 1-15 minutes. Alternatively, drying could occur ina ventilated oven at a temperature of 180° F. for a period of 2-3 hours.The drying temperature and time may vary based on an original moisturecontent of paper and plastic fragments, an intended application, andwhether and how the fragments were treated. The fragments may be driedto reduce their moisture content. The fragments may be dried to have amoisture content less than about 10%. In some embodiments the fragmentsmay be dried to have a moisture content less than about 5%.

At 350 the paper and plastic fragments are mixed. The paper fragmentsand plastic fragments may be mixed to achieve a desired paper/plasticratio. In some embodiments an amount of paper fragments and an amount ofplastic fragments may be added to a mixing vessel. A mixing vessel maybe, for example, a rotating drum blender equipped with internal flights.The amount of paper fragments and the amount of plastic fragments addedto the mixing vessel may be controlled by weigh belts and flow gates.For example, a weigh belt may send a signal to a flow gate attached to astorage bin to either open or close based on the weight belt sensingthat a current flow rate is under or over, respectively, a flow ratetarget. Other mixing devices and/or mixing procedures may be used toachieve the desired paper/plastic ratio.

At 360 the paper fragments and plastic fragments are coated with anadhesive. The adhesive may be applied to the fragments before, during,or after the fragments are mixed. For example, the adhesive may beapplied to paper fragments in a first blender while the adhesive isapplied to plastic fragments in a second blender, and then the paper andplastic fragments are mixed. In this example, different mixing devicesor systems can be used for the paper fragments and the plasticfragments. In another example, the adhesive is applied to a mixture ofpaper fragments and plastic fragments in one blender.

In some embodiments, the fragments may be coated with a liquid adhesive.The liquid adhesive may be a liquid adhesive which is sprayed at a rateconfigured to achieve a targeted adhesive level. The liquid adhesive maybe a one-component liquid or a two-component, liquid/liquid adhesive ofwhich the two components are proportionally pumped to a mixing devicebefore the resulting mixture is sprayed onto the fragments. In someembodiments the liquid adhesive may be dispensed into a blender throughone or more airless or air-assisted spray application devices. In otherembodiments, the liquid adhesive may be applied by use of a spinningdisk atomizer.

In some embodiments, the fragments may be coated with a powder adhesive.The powder adhesive may be added to the fragments in an amountconfigured to achieve a targeted adhesive level. The powder adhesive maybe dosed into a blender using an auger, screw, conveyor, blow pipe, orother means. The powder adhesive may be dosed into the blender with amass flow rate configured to achieve the targeted adhesive level. Forexample, the powder adhesive may be added to the blender at the sametime as the fragments and the flow rate of the powder adhesive will bebased on the flow rate of the fragments so as to achieve the targetedadhesive level.

In some embodiments, the adhesive may coat the paper fragments and theplastic fragments equally. In other embodiments, the adhesive may coatthe paper fragments more than the plastic fragments. In yet otherembodiments, the adhesive may coat the plastic fragments more than thepaper fragments. The adhesive may coat each fragment completely so that100% of the fragment surface area is coated with adhesive. The adhesivemay coat each fragment so that 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%,55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5% of the fragmentsurface area is coated with adhesive.

At 370 the paper fragments and the plastic fragments are formed into amat. In some embodiments the mat may be formed by dispensing fragmentsonto a conveyor belt in distinct layers. Alternatively, a first exteriorlayer 240 can be transported on a conveyor belt and fragments can bedispensed onto the exterior layer 240 in one or more layers. In yetanother embodiment, a second exterior layer 250 can be placed on top ofpreviously dispensed layers of fragments. Further yet, fragments andoptionally exterior layers can be formed into a mat by use of a formingbox. The forming box may refer to a frame with a floor. In someembodiments the forming box may have a shape corresponding to a shape ofa panel. The forming box may have dimensions larger than or equal todimensions of the pressed composite or panel. The fragments may bedistributed uniformly in the forming box. The fragments may becompressed within the forming box at a temperature of about 50-150° F.For example, the fragments may be compressed by a hydraulic press as thefragments are in the forming box. In other embodiments, the paperfragments and the plastic fragments are formed into a mat in acontinuous sheet or ribbon. For example, the fragments may be uniformlydistributed on a conveyor belt and compressed by a press or roller toform a mat that is thinner than the mat that was initially formed. Useof the aforementioned tackifying resin can help to ensure that thecompressed mat retains its thinner dimension and fragments are generallynot expelled from the left or right edges of the mat. Once formed, themat may be separated from the forming box or advanced in a continuousmanner such that the mat is transferred from the forming line to thepressing station.

At 380 the mat formed from the paper fragments and the plastic fragmentsis pressed. Pressing the mat may include pressing the mat first with ahot press and second with a cold press. The hot press may have a firsttemperature and the cold press may have a second temperature lower thanthe first temperature. The hot press may include a hot press bottomplaten and a hot press top platen. The hot press may press the matbetween the hot press bottom platen and the hot press top platen. Thecold press may include a cold press bottom platen and a cold press topplaten. The cold press may press the mat between the cold press bottomplaten and the cold press top platen. The hot press may apply a firstamount of pressure to the mat and the cold press may apply a secondamount of pressure to the mat. In some embodiments the hot press mayrapidly increase pressure on the mat to achieve a maximum hot presspressure. This maximum hot press pressure might be maintained during theremaining portion of the hot press process or the pressure might bereduced. In some embodiments, the pressure applied to the mat during hotpressing will be essentially uniform. In other embodiments, greateramounts of pressure might be applied to first regions of the mat whilelesser amounts of pressure are applied to second regions of the mat. Insome embodiments the cold press may rapidly increase pressure on the matto achieve a maximum cold press pressure. This maximum cold presspressure might be maintained during the remaining portion of the coldpress process or the pressure might be reduced. The hot press may applythe first amount of pressure a first amount of time. The cold press mayapply the second amount of pressure a second amount of time. Forexample, a hot press having a temperature of 400° F. may press a mat,rapidly increasing pressure over 1-10 seconds until it reaches apressure of about 400-800 psi. The hot press may thereafter reduce thepressure applied to the mat such that the pressure is reduced to lessthan 50 psi after a period of about 30-60 seconds. A pressure of lessthan 50 psi might be maintained on the mat for an additional period ofabout 270-300 seconds during the hot pressing event. Longer hot presstimes may be required for mats thicker than about 0.40 inches, whileshorter hot press times might be suitable for mats thinner than about0.40 inches. Use of certain adhesives, especially thermosettingadhesives, can facilitate the use of shorter hot press times. Within aperiod of about 0-120 seconds after the mat has undergone the hot pressprocess, the mat can be transferred from the hot press to the coldpress. The cold press can have a platen temperature of about 20-150° F.A pressure of about 5-50 psi can be exerted on the mat during coldpressing. The duration of cold pressing can be about 330 seconds. Longercold press times may be required for mats thicker than about 0.40inches, while shorter cold press times might be suitable for matsthinner than about 0.40 inches.

In some embodiments the mat formed from the paper fragments and theplastic fragments is a continuous sheet or ribbon and is pressed into acontinuous sheet or ribbon from which panels are cut. For example, aconveyor belt may carry the continuous mat to the hot and cold presses.The conveyor may have dimensions equal to or greater than a dimension ofthe panel. The conveyor may move the continuous mat so that a firstportion of the mat can be pressed by the hot press, cease movement whilethe hot press presses the first portion, move the continuous mat so thatthe first portion can be pressed by the cold press and a second portioncan be pressed by the cold press, cease movement while the cold presspresses the first portion and the hot press presses the second portion,and move the continuous mat so that the second portion can be pressed bythe cold press. In this way, a continuous sheet or ribbon of mat can bepressed into panel material from which individual panels may be cut. Thehot press and the cold press may be larger than the dimensions of thepanel. The hot press and the cold press may be large enough to press asection of the continuous mat equal to the area of many panels. Theremay be multiple hot presses and multiple cold presses. In anotherexample, a conveyor belt may carry the continuous mat to a continuoushot press, which comprises top and bottom thin metal belts, whichsandwich the mat. A series of rollers are used to mechanically supportand guide the top and bottom belts within the continuous hot press. Thehot press is heated by use of heated platens which are positioneddirectly behind the rollers. A continuous cold press, with cold rollers,can be positioned in-line, subsequent to the continuous hot press. Thecontinuous hot press and the continuous cold press may perform the samefunction as the batch hot press and the batch cold press of heating andcompressing, and then cooling, the mat.

Advantageously, the manufacturing process 300 assembles the mat andconsolidates it into a panel in a relatively cold state as compared toconventional methods. The cooler state requires lower energy expenditureand preserves the spatial order of the panel components throughout theprocess. The manufacturing process allows for the preparation of panelswith functional layers that yield specific mechanical or other desirableproperties. Additionally, the inclusion of large amounts of papercompared to conventional processes which utilize almost exclusivelyplastic, allows for the fine-tuning of mechanical or other desirableproperties. The fragments in each layer generally maintain theirrelative position, preserving the layer structure as well as thearrangement of fragments within each layer. Maintaining the relativeposition of the fragments allows for blends of paper and plastic to bepreserved as mixtures of paper and plastic throughout the productionprocess and in the finished panel. Maintaining the relative position ofthe fragments also allows for layers of paper and plastic to bepreserved within each layer. Additionally, producing panels in acontinuous sheet or ribbon has the advantage of greater efficiency andgreater uniformity than conventional methods which produce one panel ata time.

FIG. 4 is a flow diagram depicting operations in a panel manufacturingprocess 400, in accordance with another example embodiment. Additional,fewer, or different operations may be performed in the method, dependingon the embodiment. Further, the operations may be performed in the ordershown, concurrently, or in a different order. At 405 paper fragments ofa first size are obtained. In some embodiments, the paper fragments maybe obtained by shredding existing fragments, or by shredding largerobjects or materials. The paper fragments may be shredded from newmaterial, recycled objects or material, or even objects or materialsthat are recovered from waste streams. The shredded paper fragments maybe processed through one or more screens to obtain paper fragments ofthe first size. For example, paper fragments can be obtained by millingpieces of paper until the fragments pass through a 1-inch mesh screen.Screens with larger or smaller mesh sizes may be used. In anotherexample, paper fragments are obtained by shredding recycled paper untilthe paper fragments pass through a 19-mm mesh. If multiple screens areused, the screens may or may not have the same size apertures in themesh. In other embodiments the paper fragments of the first size areobtained without shredding. The paper fragments of the first size may bepurchased or obtained in some other manner.

At 410 plastic fragments of a second size are obtained. The second sizemay be the same or different from the first size. In some embodiments,the plastic fragments may be obtained by shredding existing fragments,or by shredding larger objects or materials. The plastic fragments maybe shredded from new material, recycled objects or material, or evenobjects or materials that are recovered from waste streams. The plasticfragments may be obtained using the same shredder used to obtain thepaper fragments of the first size or by using a different shredder. Theshredded plastic fragments may be processed through one or more screensto obtain plastic fragments of the second size. For example, plasticfragments can be obtained by milling pieces of plastic until thefragments pass through a 1-inch mesh screen. Screens with larger orsmaller mesh sizes may be used. In another example, plastic fragmentsare obtained by shredding recycled plastic until the plastic fragmentspass through a 19-mm mesh. If multiple screens are used, the screens mayor may not have the same size apertures in the mesh. In otherembodiments the plastic fragments of the first size are obtained withoutshredding. The plastic fragments of the second size may be purchased orobtained in some other manner.

At 415 paper fragments of a third size are obtained. The third size maybe the same or different from the first size and/or the second size. Insome embodiments the paper fragments may be obtained by shreddingexisting fragments, or by shredding larger objects or materials. Thepaper fragments may be shredded from new material or from recycledobjects or material. The paper fragments may be obtained using the sameshredder used to obtain the paper fragments of the first size and/or theplastic fragments of the second size or by using a different shredder.The shredded paper fragments may be processed through one or morescreens to obtain paper fragments of the third size. For example, paperfragments can be obtained by milling pieces of paper until the fragmentspass through a 1-inch mesh screen. Screens with larger or smaller meshsizes may be used. In another example, paper fragments are obtained byshredding recycled paper until the paper fragments pass through a 19-mmmesh. If multiple screens are used, the screens may or may not have thesame size apertures in the mesh. In other embodiments the paperfragments of the first size are obtained without shredding. The paperfragments of the third size may be purchased or obtained in some othermanner.

At 420 plastic fragments of a fourth size are obtained. The fourth sizemay be the same or different from the first size, the second size,and/or the third size. In some embodiments the plastic fragments may beobtained by shredding existing fragments, or by shredding larger objectsor materials. The plastic fragments may be shredded from new material orfrom recycled objects or material. The plastic fragments may be obtainedusing the same shredder used to obtain the paper fragments of the firstsize, the plastic fragments of the second size, and/or the paperfragments of the third size, or by using a different shredder. Theshredded plastic fragments may be processed through one or more screensto obtain plastic fragments of the fourth size. For example, plasticfragments can be obtained by milling pieces of plastic until thefragments pass through a 1-inch mesh screen. Screens with larger orsmaller mesh sizes may be used. In another example, plastic fragmentsare obtained by shredding recycled plastic until the plastic fragmentspass through a 19-mm mesh. If multiple screens are used, the screens mayor may not have the same size apertures in the mesh. In otherembodiments the plastic fragments of the first size are obtained withoutshredding. The plastic fragments of the fourth size may be purchased orobtained in some other manner.

At 425 the paper fragments of the first size, the plastic fragments ofthe second size, the paper fragments of the third size, and the plasticfragments of the fourth size may be treated. In some embodiments, thefragments may be treated using one or more multifunctional aldehydes ora treatment composition derived from urea and one or moremultifunctional aldehydes. Treating the fragments with one or moremultifunctional aldehydes or a treatment composition derived from ureaand one or more multifunctional aldehydes may crosslink endotoxins ofthe fragments. For example, the fragments may be treated by loading thefragments into a rotary blender and spraying the fragments with aurea-glutaraldehyde solution while rotating at 10 rpm. In someembodiments the molar ratio of urea to glutaraldehyde in the solutionmay be greater than 1. In other embodiments, the fragments may betreated using one or more antimicrobial agents.

At 430 the paper fragments of the first size, the plastic fragments ofthe second size, the paper fragments of the third size, and the plasticfragments of the fourth size may be dried. The paper fragments of thefirst size, the plastic fragments of the second size, the paperfragments of the third size, and the plastic fragments of the fourthsize may be dried separately or together. The fragments may be dried ina rotary drier. For example, the fragments may be dried in a rotarydrier with an inlet temperature of about 250° F. and an outlettemperature of about 180° F. for a period of about 1-15 minutes.Alternatively, drying could occur in a ventilated oven at a temperatureof 180° F. for a period of 2-3 hours. The drying temperature and timemay vary based on an original moisture content of the fragments, anintended application, and whether and how the fragments were treated.The fragments may be dried to reduce their moisture content. Thefragments may be dried to have a moisture content less than about 10%.In some embodiments the fragments may be dried to have a moisturecontent less than about 5%.

At 435 the paper fragments of the first size and the plastic fragmentsof the second size are mixed into a first blend. The paper fragments ofthe first size and the plastic fragments of the second size may be mixedto achieve a desired paper/plastic ratio. In some embodiments an amountof paper fragments of the first size and an amount of plastic fragmentsof the second size may be added to a mixing vessel. A mixing vessel maybe, for example, a rotating drum blender equipped with internal flights.The amount of paper fragments of the first size and the amount ofplastic fragments of the second size added to the mixing vessel may becontrolled by weigh belts and flow gates. For example, a weigh belt maysend a signal to a flow gate attached to a storage bin to either open orclose based on the weight belt sensing that a current flow rate is underor over, respectively, a flow rate target. Other mixing devices and/ormixing procedures may be used to achieve the desired paper/plasticratio.

At 440 the paper fragments of the third size and the plastic fragmentsof the fourth size are mixed into a second blend. The paper fragments ofthe third size and the plastic fragments of the fourth size may be mixedto achieve a desired paper/plastic ratio. In some embodiments an amountof paper fragments of the third size and an amount of plastic fragmentsof the fourth size may be added to a mixing vessel. A mixing vessel maybe, for example, a rotating drum blender equipped with internal flights.The amount of paper fragments of the third size and the amount ofplastic fragments of the fourth size added to the mixing vessel may becontrolled by weigh belts and flow gates. For example, a weigh belt maysend a signal to a flow gate attached to a storage bin to either open orclose based on the weight belt sensing that a current flow rate is underor over, respectively, a flow rate target. Other mixing devices and/ormixing procedures may be used to achieve the desired paper/plasticratio.

At 445 the paper fragments of the third size and the plastic fragmentsof the fourth size of the second blend are coated with an adhesive. Theadhesive may be applied to the fragments before, during, or after thefragments are mixed. For example, the adhesive may be applied to thepaper fragments of the third size in a first blender while the adhesiveis applied to plastic fragments of the fourth size in a second blender,and then the paper and plastic fragments are mixed. In this example,different mixing devices or systems can be used for the paper fragmentsand the plastic fragments. In another example, the adhesive is appliedto mixed paper fragments of the third size and plastic fragments of thefourth size in one blender.

In some embodiments, the fragments may be coated with a liquid adhesive.The liquid adhesive may be a liquid adhesive which is sprayed at a rateconfigured to achieve a targeted adhesive level. The liquid adhesive maybe a one-component or a two-component, liquid/liquid adhesive of whichthe two components are proportionally pumped to a mixing device beforethe resulting mixture is sprayed onto the fragments. In some embodimentsthe liquid adhesive may be dispensed into a blender through one or moreairless or air-assisted spray application devices. In other embodiments,the liquid adhesive may be applied by use of a spinning disk atomizer.

In some embodiments, the fragments may be coated with a powder adhesive.The powder adhesive may be added to the fragments in an amountconfigured to achieve a targeted adhesive level. The powder adhesive maybe dosed into a blender using an auger, screw, conveyor, blow pipe, orother means. The powder adhesive may be dosed into the blender with amass flow rate configured to achieve the targeted adhesive level. Forexample, the powder adhesive may be added to the blender at the sametime as the fragments and the flow rate of the powder adhesive will bebased on the flow rate of the fragments so as to achieve the targetedadhesive level.

In some embodiments, the adhesive may coat the paper fragments of thethird size and the plastic fragments of the fourth size equally. Inother embodiments, the adhesive may coat the paper fragments more thanthe plastic fragments. In yet other embodiments, the adhesive may coatthe plastic fragments more than the paper fragments. The adhesive maycoat each fragment completely so that 100% of the fragment surface areais coated with adhesive. The adhesive may coat each fragment so that95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%,25%, 20%, 15%, 10%, or 5% of the fragment surface area is coated withadhesive.

At 450 a first layer is formed using the first blend. In someembodiments the first layer may be formed by placing the fragments ofthe first blend into a forming box. The forming box may refer to aclosed box or a continuous line, also termed a forming line, in whichlayers or a mat formed from layers are formed. In some embodiments, theforming box may have a shape corresponding to a shape of a panel. Theforming box may have dimensions larger than or equal to dimensions ofthe panel. The fragments of the first blend may be distributed uniformlyin the forming box. The fragments of the first blend may be compressedwithin the forming box. For example, the fragments of the first blendmay be compressed by a hydraulic press. In other embodiments, the paperfragments of the first blend and the plastic fragments of the firstblend are formed into a first layer in a continuous sheet or ribbon. Forexample, the fragments of the first blend may be uniformly distributedon a conveyor belt and compressed by a press or roller. In anotherexample, the first layer may be formed by dispensing fragments of thefirst blend onto a conveyor belt without pressing or rolling.

At 455 a second layer is formed using the second blend. In someembodiments the second layer may be formed by placing the fragments ofthe second blend into a forming box on top of the first layer. In someembodiments, the forming box may have a shape corresponding to a shapeof a panel. The forming box may have dimensions larger than or equal todimensions of the panel. The fragments of the second blend may bedistributed uniformly in the forming box. The fragments of the secondblend may be compressed within the forming box. For example, thefragments of the second blend may be compressed by a hydraulic press. Inother embodiments, the paper fragments of the second blend and theplastic fragments of the second blend are formed into a second layer ina continuous sheet or ribbon. For example, the fragments of the secondblend may be uniformly distributed on a conveyor belt on top of thefirst layer and compressed by a batch press, a continuous press, or oneor more rollers. In another example, the second layer may be formed bydispensing fragments of the second blend onto a conveyor belt withoutpressing or rolling.

At 460 a third layer is formed using the first blend. In someembodiments the third layer is formed using a third blend. In someembodiments, the third layer may be formed by placing the fragments ofthe first blend into a forming box on top of the first layer and thesecond layer. In some embodiments the forming box may have a shapecorresponding to a shape of a panel. The forming box may have dimensionslarger than or equal to dimensions of the panel. The fragments of thefirst blend may be distributed uniformly in the forming box. Thefragments of the first blend may be compressed within the forming box.For example, the fragments of the first blend may be compressed by ahydraulic press. In other embodiments, the paper fragments of the firstblend and the plastic fragments of the first blend are formed into athird layer in a continuous sheet or ribbon. For example, the fragmentsof the first blend may be uniformly distributed on a conveyor belt ontop of the first layer and the second layer and compressed by a batchpress, a continuous press, or one or more rollers. In another example,the first layer may be formed by dispensing fragments of the first blendonto a conveyor belt without pressing or rolling. The first layer, thesecond layer, and the third layer may form a mat. In some embodimentsthe mat formed from the first layer, the second layer, and the thirdlayer may be a continuous sheet or ribbon. The mat may be separated fromthe forming box.

At 465 the first layer, the second layer, and the third layer areconsolidated into a panel using heat and pressure. Consolidating thefirst layer, the second layer, and the third layer into a panel usingheat and pressure may include pressing the mat formed of the firstlayer, the second layer, and the third layer first with a hot press andsecond with a cold press. The hot press may have a first temperature andthe cold press may have a second temperature lower than the firsttemperature. The hot press may include a hot press bottom platen and ahot press top platen. The hot press may press the mat between the hotpress bottom platen and the hot press top platen. The cold press mayinclude a cold press bottom platen and a cold press top platen. The coldpress may press the mat between the cold press bottom platen and thecold press top platen. The hot press may apply a first amount ofpressure to the mat and the cold press may apply a second amount ofpressure to the mat. The hot press may rapidly increase pressure on themat to achieve a maximum hot press pressure. This maximum hot presspressure might be maintained during the remaining portion of the hotpress process or the pressure might be reduced. In some embodiments, thepressure applied to the mat during hot pressing will be essentiallyuniform. In other embodiments, greater amounts of pressure might beapplied to regions of the mat, while lesser amounts of pressure areapplied to different regions of the mat. The cold press may rapidlyincrease pressure on the mat to achieve a maximum cold press pressure.This maximum cold press pressure might be maintained during theremaining portion of the cold press process or the pressure might bereduced. The hot press may apply the first amount of pressure a firstamount of time. The cold press may apply the second amount of pressure asecond amount of time. For example, a hot press having a temperature of400° F. may press the mat, rapidly increasing pressure over 1-10 secondsuntil it reaches a pressure of about 400-800 psi. The hot press maythereafter reduce the pressure applied to the mat such that the pressureis reduced to less than 50 psi after a period of about 30-60 seconds. Apressure of less than 50 psi might be maintained on the mat for anadditional period of about 270-300 seconds during the hot pressingevent. Longer hot press times may be required for mats thicker thanabout 0.40 inches, while shorter hot press times might be suitable formats thinner than about 0.40 inches. Use of adhesive, especially athermosetting adhesive, can facilitate the use of shorter hot presstimes. Within a period of about 0-120 seconds after the mat hasundergone the hot press process, the mat can be transferred from the hotpress to the cold press. The cold press can have a platen temperature ofabout 20-150° F. A pressure of about 5-50 psi can be exerted on the matduring cold pressing. The duration of cold pressing can be about 330seconds. Longer cold press times may be required for mats thicker thanabout 0.40 inches, while shorter cold press times might be suitable formats thinner than about 0.40 inches.

In some embodiments, the mat formed from the first layer, the secondlayer, and the third layer is a continuous sheet or ribbon and isconsolidated into a continuous sheet or ribbon from which panels arecut. For example, a conveyor belt may carry the continuous mat to thehot and cold presses. The conveyor may have dimensions equal to orgreater than a dimension of the panel. The conveyor may move thecontinuous mat so that a first portion of the mat can be pressed by thehot press, cease movement while the hot press presses the first portion,move the continuous mat so that the first portion can be pressed by thecold press and a second portion can be pressed by the cold press, ceasemovement while the cold press presses the first portion and the hotpress presses the second portion, and move the continuous mat so thatthe second portion can be pressed by the cold press. In this way, acontinuous sheet or ribbon of mat formed from the first layer, thesecond layer, and the third layer can be consolidated into panelmaterial from which individual panels may be cut. The hot press and thecold press may be larger than the dimensions of the panel. The hot pressand the cold press may be large enough to press a section of thecontinuous mat equal to the area of many panels. There may be multiplehot presses and multiple cold presses. In another example, a conveyorbelt may carry the continuous mat to hot rollers and cold rollers. Thehot rollers and the cold rollers may perform the same function as thehot press and the cold press of heating and compressing the mat. Theconveyor belt may not need to cease movement when the continuous mat ispressed by the hot rollers and the cold rollers. In yet anotherembodiment, a conveyor belt may carry the continuous mat to a continuoushot press, which comprises top and bottom thin metal belts, whichsandwich the mat. A series of rollers are used to mechanically supportand guide the top and bottom belts within the continuous hot press. Thehot press is heated by use of heated platens which are positioneddirectly behind the rollers. A continuous cold press, with cold rollers,can be positioned in-line, subsequent to the continuous hot press. Thecontinuous hot press and the continuous cold press may perform the samefunction as the batch hot press and the batch cold press of heating andcompressing, and then cooling, the mat.

At 470 intractable surface layers are attached to the top and bottomsurfaces of the panel. The top and bottom surfaces of the panel may bethe first layer and the third layer. An intractable material is apolymeric material which is insoluble in water, and which has a meltingpoint greater than about 350° F. For example, an intractable materialmay be paper, wood veneer, woven cellulosic fabrics, hydroentangledcellulosic nonwoven fabrics, nylon film, polyester film, nylon nonwovenfabrics, polyester glass woven roving, metallic foils, or other thinsheet or roll goods having a melting point above 350° F. In someembodiments, the first exterior layer 240 and the second exterior layer250 include an intractable material having a melting point greater than450° F. or an intractable material having no recognized melting point.The intractable surface layers may be attached to the first layer andthe third layer by a thermoplastic adhesive, a thermosetting adhesive,or a mechanical fastening system. The intractable surface layers may beattached to the panel using the same thermosetting adhesive as was usedto coat the fragments of the first, second, and/or third layers.

In some embodiments, the intractable surface layers are assembled intothe mat prior to the hot press event. For example, the intractablesurface layers may be coated on the fragment-facing surface with athermosetting adhesive which is cured as the mat formed of the firstlayer, the second layer, and the third layer is consolidated into apanel at elevated temperature. In other embodiments, the intractablesurface layers are attached to the panel after the layers areconsolidated into a panel. For example, the intractable surface layersmay be attached to the panel using mechanical fastening means such asbolts, screws, or staples after the layers have been consolidated into apanel. The intractable surface layers may cover the entire surface areaof the panel’s exterior faces or only a portion of the panel’s exteriorfaces. The intractable surface layers may cover identical or mirrorareas of the panel on opposite exterior surfaces of the panel. Theintractable surface layers may have a thickness greater than about0.00001 inches and less than about 0.20 inches. The intractable surfacelayers may together be about 1-20% of the panel by weight. In someembodiments only one intractable surface layer is attached to the panel.

In some embodiments, the intractable surface layers are not attached tothe panel after the panel is formed but are incorporated into the panelas the layers of the mat are being formed. For example, the first,second, and third layers may be formed by placing fragments on top of afirst intractable surface layer. A second intractable surface layer maybe placed on top of the first, second, and third layers to sandwich thefirst, second, and third layers between the first and second intractablesurface layers. The mat formed of the first, second, and third layerssandwiched between the first and second intractable surface layers maybe pressed to consolidate the layers into a panel. In another example,the first, second, and third layers may be formed by dispensingfragments on top of a first intractable surface layer on a conveyorbelt. A second intractable surface layer may be placed on top of thefirst, second, and third layers to form a mat including the first,second, and third layers sandwiched between the first and secondintractable surface layers. In this example, the mat including thefirst, second, and third layers sandwiched between the first and secondintractable surface layers may be formed in a continuous sheet orribbon. The continuous mat may be consolidated into a continuous panelusing heat and pressure by continuous hot and cold presses, as discussedherein.

Advantageously, the manufacturing process 400 assembles the mat andconsolidates it into a panel in a relatively cold state as compared toconventional methods. This process requires lower energy expenditure andpreserves the spatial order of the panel components throughout theprocess. Preserving the spatial order of the panel components allows thepanel to be constructed from multiple layers each having a uniquemakeup. Each layer can have its own blend of fragments having uniquesizes. Each layer can have additional complexity, such as layers ofdifferent materials. Building a panel from multiple layers, theproperties of which can be fine-tuned results in panels withadvantageous mechanical properties. For example, panels built out oflayers of material such as discussed herein have higher bond strength,higher bending strength, and higher moduli of elasticity thanconventional panels without layers. Additionally, the use of athermosetting adhesive has the advantage of reducing the time needed topress the panel as compared to conventional panels without thermosettingadhesives. The use of a thermosetting adhesive also advantageouslyincreases bond strength without increasing the thermal expansioncoefficient as compared to conventional methods of increasing bondstrength in panels. Using a thermosetting adhesive may also have theadvantage of increasing the water resistance of the panel. Somethermosetting resins also impart tack to the fragments. Thus, using somethermosetting adhesives may also have the advantage of simplifying themanufacturing process as mats containing a thermosetting adhesive holdtogether better than mats without a thermosetting adhesive. Fragmentsare less likely to become detached from a panel having a tackythermosetting adhesive prior to pressing than from a panel without atacky thermosetting adhesive. Fragments becoming detached may accumulateon forming boxes, conveyor belts, and/or presses. Fragments thataccumulate on presses may ignite if not removed. Thus, using a tackythermosetting adhesive reduces monitoring and cleaning costs, whileincreasing the safety of the panel manufacturing process. Additionally,producing panels in a continuous sheet or ribbon has the advantage ofgreater efficiency and greater uniformity than conventional methodswhich produce one panel at a time.

FIG. 5 is a table 500 comparing various example panels, in accordancewith various embodiments. The table 500 compares various characteristicsof example panels 2c, 3a and 3b. Example panel 3a was prepared byshredding paper and plastic fragments, drying the fragments, mixing thepaper fragments and the plastic fragments to achieve a 70:30 blend ofpaper fragments and plastic fragments, placing the fragments in aforming box such that the fragment layer was sandwiched betweenpolyethylene film (3.0 mil) in direct contact with the fragments and42-pound kraft paper in direct contact with the polyethylene film,removing the mat assembly from the forming box, pressing the matassembly with a hot press with a platen temperature of 400° F. and aconstant pressure of 29 psi, and then pressing the fragments with a coldpress with a platen temperature of 45° F. and a constant pressure of 17psi for a period of 300 s, in accordance with one or more embodiments.Samples of the example panel 3a were removed and tested to obtain themechanical properties of the example panel 3a shown in the table 500.Example panel 3b was prepared in a similar manner to example panel 3aexcept that example panel 3b was prepared with the fragments beingcoated with adhesive. Example panel 2c was prepared in similar manner tothe example panel 3a except that the example panel 2c was prepared witha 74:26 blend of paper fragments and plastic fragments. Example panel 2calso had two separate thin fragment surface layers (40:60 blend of paperfragments and plastic fragments) and a thick fragment core layer (80:20blend of paper fragments and plastic fragments), the core layer beingcoated with an adhesive. Example panel 2c was also prepared with a hotpress time that was 30 seconds shorter than that of example panels 3aand 3b.

The table 500 shows that use of an adhesive on the fragments cansignificantly increase the bending strength and stiffness of the panel(see example panels 3a versus 3b). Surprisingly, use of adhesive inconjunction with separate fragment layers (see example panel 2c) furtherincreased the bending strength and stiffness of the panel, in spite ofthe reduction in hot press time and adhesive level. The mechanicalproperty improvements associated with example panel 2c are unexpectedlylarge. Classic beam theory teaches us to improve the bending propertiesof a composite panel (having fixed dimensions) by increasing the modulusof the outer-most layers. This same theory teaches us that increasingthe modulus of the inner-most layer of the composite should have arelatively small impact on stiffness. The thermosetting adhesive is onlybeing used in the center-most region of the panel with a layeredfragment structure. This center-most layer is sometimes referred to asthe neutral axis, because this layer typically does not affect thebending properties of the panel. Thus, these results are surprising andunexpected.

In an illustrative embodiment, any of the operations described hereincan be implemented at least in part as computer-readable instructionsstored on a computer-readable memory. Upon execution of thecomputer-readable instructions by a processor, the computer-readableinstructions can cause a node to perform the operations.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely exemplary, and that in fact many other architectures can beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality can be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable,” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents and/or wirelessly interactable and/or wirelessly interactingcomponents and/or logically interacting and/or logically interactablecomponents.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to inventions containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.” Further, unlessotherwise noted, the use of the words “approximate,” “about,” “around,”“similar,” “substantially,” etc., mean plus or minus ten percent.

The foregoing description of illustrative embodiments has been presentedfor purposes of illustration and of description. It is not intended tobe exhaustive or limiting with respect to the precise form disclosed,and modifications and variations are possible in light of the aboveteachings or may be acquired from practice of the disclosed embodiments.It is intended that the scope of the invention be defined by the claimsappended hereto and their equivalents.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

1. A panel comprising: a first layer comprising a thermoplastic binderand a first blend of paper fragments and plastic fragments; a secondlayer comprising a second blend of paper fragments and plasticfragments, wherein the paper fragments and plastic fragments of thesecond blend are coated with a thermosetting resin; and a third layercomprising a thermoplastic binder and the first blend of paper fragmentsand plastic fragments, wherein the second layer is disposed between thefirst layer and the third layer, and wherein the first layer, the secondlayer, and the third layer are combined to form the panel using heat andpressure.
 2. The panel of claim 1 wherein the paper and plasticfragments of the first and second blends comprise recycled wastematerial.
 3. The panel of claim 1 wherein, the first blend includespaper fragments of a first size and plastic fragments of a second size,and the second blend includes paper fragments of a third size andplastic fragments of a fourth size.
 4. The panel of claim 1 wherein thefirst blend comprises a first paper to plastic ratio and the secondblend comprises a second paper to plastic ratio.
 5. The panel of claim 1wherein the paper and plastic fragments of the first and second blendsare dried to have a moisture content less than about 10%.
 6. The panelof claim 1 wherein the paper and plastic fragments are treated with oneor more multifunctional aldehydes or a treatment composition derivedfrom urea and one or more multifunctional aldehydes.
 7. The panel ofclaim 1 wherein coating the paper fragments and plastic fragments of thesecond blend with the thermosetting resin comprises combining thefragments with the thermosetting resin as they are mixed into the secondblend.
 8. The panel of claim 1 wherein the first layer, the secondlayer, and the third layer are combined to form the panel using heat andpressure by: forming the first layer, the second layer, and the thirdlayer into a mat; pressing the first layer, the second layer, and thethird layer using a first press having a first temperature; and pressingthe first layer, the second layer, and the third layer using a secondpress having a second temperature, wherein the second temperature islower than the first temperature.
 9. The panel of claim 8 whereinforming the first layer, the second layer, and the third layer into amat comprises: dispensing a first amount of paper and plastic fragmentsof the first blend onto a conveyor belt to form the first layer;dispensing a second amount of paper and plastic fragments of the secondblend onto the conveyor belt on top of the first layer to form thesecond layer; and dispensing a third amount of paper and plasticfragments of the first blend onto the conveyor belt on top of the secondlayer to form the third layer.
 10. The panel of claim 1 furthercomprising: a first intractable layer on a first outside surface of thepanel; and a second intractable layer on a second outside surface of thepanel.
 11. A method for manufacturing a panel comprising: obtainingpaper fragments and plastic fragments; mixing a first portion of thepaper fragments and a first portion of the plastic fragments into afirst blend of paper and plastic fragments; mixing a second portion ofthe paper fragments and a second portion of the plastic fragments into asecond blend of paper and plastic fragments; coating the paper fragmentsand the plastic fragments of the first blend with a thermoplasticbinder; coating the paper fragments and the plastic fragments of thesecond blend with a thermosetting resin; forming a first layercomprising the first blend; forming a second layer comprising the secondblend; forming a third layer comprising the first blend, wherein thesecond layer is disposed between the first and third layers; andconsolidating the first layer, the second layer, and the third layerinto the panel using heat and pressure.
 12. The method of claim 11wherein the paper and plastic fragments comprise recycled wastematerial.
 13. The method of claim 11 wherein, the first blend includespaper fragments of a first size and plastic fragments of a second size,and the second blend includes paper fragments of a third size andplastic fragments of a fourth size, wherein the first size is differentthan the third size and the second size is different than the fourthsize.
 14. The method of claim 11 wherein mixing the paper fragments andthe plastic fragments into a first blend includes combining the paperfragments and the plastic fragments in a first paper to plastic ratio,and wherein mixing the paper fragments and the plastic fragments into asecond blend includes combining the paper fragments and the plasticfragments in a second paper to plastic ratio, wherein the first paper toplastic ratio is different than the second paper to plastic ratio. 15.The method of claim 11 further comprising drying the paper and plasticfragments of the first and second blends to have a moisture content lessthan about 10%.
 16. The method of claim 11 further comprising treatingthe paper and plastic fragments with one or more multifunctionalaldehydes or a treatment composition derived from urea and one or moremultifunctional aldehydes.
 17. The method of claim 11 wherein coatingthe paper fragments and plastic fragments of the second blend with thethermosetting resin comprises spraying or coating the fragments with thethermosetting resin as they are mixed into the second blend.
 18. Themethod of claim 11 wherein consolidating the first layer, the secondlayer, and the third layer into the panel by using heat and pressurecomprises: forming the first layer, the second layer, and the thirdlayer into a mat; pressing the first layer, the second layer, and thethird layer using a first press having a first temperature; and pressingthe first layer, the second layer, and the third layer using a secondpress having a second temperature, wherein the second temperature islower than the first temperature.
 19. The method of claim 18 whereinforming the first layer, the second layer, and the third layer into amat comprises: dispensing a first amount of paper and plastic fragmentsof the first blend onto a conveyor belt to form the first layer;dispensing a second amount of paper and plastic fragments of the secondblend onto the conveyor belt on top of the first layer to form thesecond layer; and dispensing a third amount of paper and plasticfragments of the first blend onto the conveyor belt on top of the secondlayer to form the third layer.
 20. The method of claim 19 furthercomprising: placing a second intractable surface layer on top of thethird layer, wherein dispensing the first amount of paper and plasticfragments of the first blend onto the conveyor belt to form the firstlayer comprises dispensing the first amount of paper and plasticfragments of the first blend onto a first intractable surface layer onthe conveyor belt and wherein pressing the first layer, the secondlayer, and the third layer using the first press having the firsttemperature and pressing the first layer, the second layer, and thirdlayer using the second press having the second temperature comprisespressing the first layer, the second layer, and the third layer betweenthe first and second intractable surface layers. 21-23. (canceled)
 24. Apanel comprising: a first layer comprising a first blend of paperfragments and plastic fragments, wherein the paper fragments and plasticfragments of the first blend are coated with a thermoplastic binder; asecond layer comprising a second blend of paper fragments and plasticfragments, wherein the paper fragments and plastic fragments of thesecond layer are coated with a thermosetting resin; and a third layercomprising the third blend of paper fragments and plastic fragments,wherein the paper fragments and plastic fragments of the third blend arecoated with the thermoplastic binder; wherein the second layer isdisposed between the first layer and the third layer, and wherein thefirst layer, the second layer, and the third layer are combined to formthe panel using heat and pressure.
 25. The panel of claim 24, whereincoating the paper fragments and plastic fragments of the first and thirdblends with the thermoplastic binder comprises combining the fragmentswith thermoplastic binder as they are mixed into the first and thirdblends.
 26. The panel of claim 24, wherein the first layer, the secondlayer, and the third layer are combined to form the panel using heat andpressure by: forming the first layer, the second layer, and the thirdlayer into a mat; pressing the first layer, the second layer, and thethird layer in a first pressing event associated with a firsttemperature; and pressing the first layer, the second layer, and thirdlayer in a second pressing event associated with a second temperature,wherein the second temperature is lower than the first temperature. 27.The panel of claim 24, wherein the first layer, the second layer, andthe third layer are combined to form the panel using heat and pressureby: forming the first layer, the second layer, and the third layer intoa mat; pressing the first layer, the second layer, and the third layerin a first pressing event associated with a first temperature; andpressing the first layer, the second layer, and third layer in a secondpressing event associated with a second temperature, wherein the secondtemperature is lower than the first temperature.
 28. The panel of claim24, further comprising: a first intractable layer on a first outsidesurface of the panel; and a second intractable layer on a second outsidesurface of the panel, wherein the first and second intractable layersare attached to the panel via a thermoplastic adhesive, a secondthermosetting adhesive, or a mechanical fastening. 29-33. (canceled)